Powered capstan cable pulling mechanism



April 29, 1969 M. E. JONES POWERED CAPSTAN CABLE PULLING MECHANISM Filed June 22, 1967 INVENTOR. BMILTON EARL JONES I A TORNEYS United States Patent 3,440,896 POWERED 'CAPSTAN CABLE PULLING MECHANISM Milton Earl Jones, 357 Athol Ave., Oakland, Calif. 94606 Filed June 22, 1967, Ser. No. 648,143

Int. Cl. B66d N74 US. Cl. 74-413 6 Claims ABSTRACT OF THE DISCLOSURE position therearound.

Background of the invention Various powered pulling units are available to expedite the pulling of cable and other electrical conductors through the restricted passage defined by a conduit, in order to reduce the construction time and cost of an electrical installation. Such units generally include a support frame with a winch mounted thereon. A pull line wound about a drum of the winch is guided by means of pulleys on the frame into a conduit for securance at the opposite end of the conduit to a cable, or electrical conductors to be pulled therethrough. The winch is typically provided with a power input shaft which may be gripped by the chuck of a standard electrical hand power drill, or similar power tool, in order to effect powered rotation of the drum. As the drum turns, the pull line is hence wound thereon to in turn pull the cable, etc., through the conduit. It will be thus appreciated that conventional winch mechanism of cable pulling units has required an auxiliary power source, and moreover the torque developed by the drum has been relatively low due to the limited available space in which appropriate speed reduction gearing may be installed between the power input shaft and drum. In addition, the drum has usually been captive insofar as both ends have been obstructed, thereby limiting manipulation of the pull line about the drum to the central region thereof.

Summary of the invention The present invention overcomes the limitations and disadvantages of conventional winch mechanisms of the type employed in cable pulling units by providing a compact powered pulling mechanism with a self-contained power source and which yet includes reduction gearing of a type conducive to the development of a relatively large torque in the rotary pulling element thereof. The pulling element of the mechanism is provided as a free ended capstan to facilitate increased freedom of manipulation of the pull line therearound.

Brief description of the drawing FIGURE 1 is a perspective view of a preferred embodiment of a powered capstan cable pulling mechanism in accordance with the present invention.

FIGURE 2 is an exploded plan view of the mechanism.

FIGURE 3 is a fragmentary plan view with portions broken away of the mechanism, illustrating the cooperation between various of the gearing components thereof.

Description of the preferred embodiment As shown in FIGURES 1 and 2, the powered capstan cable pulling mechanism of the present invention includes a free ended capstan 11 and electric motor 12 mounted in parallel juxtaposition upon a bracket 13 and rotatably coupled by gearing of a type subsequently described. The motor 12 is preferably of the high torque gearmotor type, such as manufactured by Lamb Electric, a division of Ametek, Inc., Kent, Ohio, and outlined in their Bulletin 3101, Apr. 1963. The motor is mounted on a base portion 14 of bracket 13 which projects perpendicularly from a vertical wall portion 16 thereof. The motor shaft 17 extends through the wall portion 16 in free rotatable relation thereto and a spur gear 18 is carried on the projecting free end of the shaft.

To facilitate rotatable mounting of the capstan 11, a stub shaft 19 projects normally from the wall portion 16 in parallel spaced relation to the motor shaft 17. The capstan is preferably of hollow substantially bell-shaped configuration including a, cylindrical drum portion 21 which is inwardly tapered from a slightly enlarged outer end and terminates inwardly in an outwardly flared annular flange 22. The capstan is formed interiorly with a coaxial bushing 23 for receiving the stub shaft 19 in rotatable relation. In this regard, the shaft is preferably fitted With a sleeve 24 of suitable material such as bronze, so :as to present a good rotatable bearing surface to the capstan bushing 23. Retention of the capstan on the stub shaft is facilitated as by means of a retaining disc 26 secured to the end of the shaft by a bolt 27, or the like. The disc projects outwardly from the shaft periphery to abut the end of the bushing and thus provide the desired capstan retention. Access to the retaining disc is advantageously afforded by an opening 28 in the free, or outer end of the capstan body, which opening is normally closed as by means of a removable cover plate 29.

Considering now the gearing for coupling the motor 12 to the capstan 11, it is to be noted that a spur gear 31 of substantially larger diameter than gear 18 is secured to a shaft 32 which is journalled in bracket wall portion 16 at a point eccentrically related to stub shaft 19. Gear 31 meshes with gear 18 on the opposite side of wall portion 16 to capstan 11 and motor 12, and the opposite end of shaft 32 carries a spur gear 33 of small diameter relative to gear 31. It is of importance to note that the inner periphery of the capstan flange 22 is toothed so as to define a ring gear 34 which meshes with gear 33 and is of substantially larger diameter. Thus, motor 12 rotates gear 18 which in turn drives gear 31. Gear 31 drives gear 33, and thus ring gear 34, to rotatably drive the capstan 11.

It will be appreciated that by virtue of the juxtaposed mounting of the capstan 11 and motor 12, and the above described gearing arrangement therebetween, an extreme- 1y compact cable pulling mechanism is provided. In addition, the reduction gearing is such as to materially enhance the already high torque delivered by the motor to the capstan. In as much as the free end of the capstan is totally unobstructed, substantial ease in manipulating the pull cable around the capstan is provided.

What is claimed is:

1. Cable pulling mechanism comprising a motor, a capstan, means mounting said motor and capstan in parallel juxtaposition, and speed reduction gearing coupling said motor in driving relation to said capstan, including means defining a ring gear on said capstan, a spur gear having a small diameter relative to said ring gear, said spur gear eccentrically related to said capstan and meshing with said ring gear, a second spur gear of large diameter relative to said first gear and shaft connected therewith, and a third spur gear of small diameter relative to said second spur gear and meshing with same, said third spur gear carried by the drive shaft of said motor.

2. Cable pulling mechanism comprising a motor, a cap stan, means mounting said motor and capstan in parallel juxtaposition, and speed reduction gearing coupling said motor in driving relation to said capstan, said mounting means comprising a bracket having a base portion projecting normally from a vertical wall portion, and wall portion having a stub shaft projecting normally therefrom on the same side as said base portion and spaced therefrom, said motor mounted on said base portion with a drive shaft extending through said wall portion, said capstan being of hollow bell-shaped configuration including an internal bushing receiving said stub shaft, said capstan having an internally geared portion defining a ring gear, and said gearing including a spur gear carried on a second shaft journalled in said wall portion at a point eccentrically related to said stub shaft, said spur gear meshing with said ring gear, said second shaft carrying a second spur gear on the opposite side of said wall portion from said first spur gear, and a third spur gear carried by said motor drive shaft and meshing with said second spur gear.

3. Cable pulling mechanism according to claim 2, further defined by said first and third spur gears having small diameters relative to said second spur gear and said ring gear.

4. Cable pulling mechanism according to claim 3, further defined by said motor being a high torque gear motor 5. Cable pulling mechanism according to claim 4, further defined by a retaining disc secured to the end of said stub shaft and projecting outwardly therefrom into engagement with the end of said bushing, said capstan having an opening in its free end, and a removable cover plate secured to said capstan in closing relation to said bushing.

6. Cable pulling mechanism comprising a capstan, mounting means for said capstan including a wall portion having a stub shaft projecting generally normally therefrom, said capstan coaxially receiving said stub shaft at one end and being mounted thereon for coaxial rotation with respect thereto, a motor, and speed reduction gearing coupling said motor in driving relation to said capstan adjacent the end of said capstan receiving said stub shaft, the other end of said capstan being free of mounting and driving means so as to provide said capstan with one free end facilitating wrapping therearound of a pull line.

References Cited UNITED STATES PATENTS 1,585,065 5/1926 Wilsing 74-421 2,832,229 4/1958 Rieser 74-421 3,227,420 1/1966 Scott 254175.7

DONLEY J. STOCKING, Primary Examiner.

LEONARD H. GERIN, Assistant Examiner.

US. Cl. X.R. 254175.7 

